1. Field of the Invention
This invention relates to an optical disk apparatus, and more particularly to an optical disk apparatus provided with a fan adapted to generate a cooling air current to occur in the interior of a case body.
2. Description of the Related Art
The techniques for making it difficult to exert the influence of the heat generated by electronic parts upon an optical disk by employing a structure in which the interior of a case housing therein the optical disk and an electronic part-mounted wiring board is divided by an intermediate case member into a first spatial region in which the optical disk is housed and a second spatial region in which the electronic parts are housed, and the techniques for utilizing for the cooling purpose an air current occurring owing to the rotation of the optical disk in the interior of the case have heretofore been known (refer to, for example, JP-A-2003-249067). In addition, the techniques for preventing the overheating of circuit elements mounted on a substrate board, and the techniques for increasing the cooling efficiency in an information processing apparatus have been proposed (refer to, for example, JP-A-2000-3586 or JP-A-10-172277).
Among these techniques, the disk apparatus disclosed in JP-A-2000-3586 is schematically shown in FIG. 6, and the cooling fan-carrying CD-ROM drive, which is disclosed in JP-A-10-172277, in section in FIG. 7. In the disk apparatus disclosed in JP-A-2000-3586, and as shown in FIG. 6, the air enters a vent hole 2 in a front panel 1, passes through an opening provided in a substrate board 3, passes through a space between the substrate board 3 and a unit mechanism 5 thereabove, and is guided to the outside of the disk apparatus as shown by an arrow by a fan 7 provided on an outer surface of a main frame 6. It is said that, according to this disk apparatus, a temperature rise due to the heat generated by the circuit elements provided above the substrate board 3 decreases. In the disk apparatus disclosed in JP-A-10-172277, and as shown in FIG. 7, an air current setting fan frame 10 surrounding a cooling fan 9, which is mounted on one end of a spindle 8 for rotating a CD-ROM disk D, is provided for the same cooling fan 9, the fan frame 10 being provided vertically on an outer surface of a bottom frame 11. It is said that this structure attains an increase in the cooling efficiency in the interior of the information processing apparatus.
However, in the disk apparatus disclosed in JP-A-2003-249067, a natural flow of the air occurring in the interior of the case or an air current occurring due to the rotation of the optical disk is merely utilized for cooling the optical disk. In such a cooling system, the heat generated in the drive unit and the like for the optical disk cannot be held down satisfactorily in some cases.
On the other hand, the optical disk apparatuses disclosed in JP-A-2000-3586 and JP-A-10-172277 are optical disk apparatuses adapted to generate an air current forcibly by rotating a fan. Therefore, it is considered that the quantity of the air used for cooling these optical disk apparatuses becomes large to cause a cooling effect to be heightened as compared with that of the air used for cooling the optical disk apparatus disclosed in JP-A-2003-249067.
However, in the techniques disclosed in JP-A-2000-3586, only the effect of discharging the air inside the main frame 6, which corresponds to the case body, to the outside by the fan fixed to the main frame is displayed. In the techniques disclosed in JP-A-10-172277, only the effect of discharging the air inside the bottom frame 11 to the outside by the cooling fan 9 is displayed owing to the air current setting fan frame 10 provided on the bottom frame 11 corresponding to the case body.
In view of the above, the techniques disclosed in JP-A-2000-3586 and JP-A-10-172277 do not enable the controlling on the inner side of the case body of the path of a flow of the air current occurring in the interior of the case body to be done. Therefore, in a case where a drive unit which generates heat is provided in a predetermined position in the interior of, for example, a case body of an optical disk apparatus with comparatively wide spaces formed on one side or both sides of the drive unit, the following problems arise. In such a case, an air current occurring in the interior of the case body due to the rotation of a fan passes in large quantities through the spaces in which a flow resistance is low on the left and right sides of the drive unit even when the techniques disclosed in the Patent Publication 2 and Patent Publication 3 are applied to this case. Therefore, the air current is not efficiently used for holding down the generation of heat of the drive unit.
Providing as a single part a partition member like an air current setting plate in a predetermined position has heretofore been generally carried out as a means for passing a large quantity of air current through the interior of a drive unit while controlling the air current in the interior thereof. However, when this means is employed, it becomes certainly necessary to secure an extra space for installing the current setting plate, so that the number of parts besides the air current setting plate which are needed to install the air current plate, such as fasteners increases.